Exercise machines intended to provide a cardiovascular workout often include a sensor or sensors capable of detecting, measuring, or monitoring a physiological condition of a user. Displaying the information associated with the physiological condition allows the user to adjust the intensity of their workout (e.g., to achieve or maintain a target heart rate). More importantly, the information could serve as a precautionary measure for those with health or safety concerns. For example, a person with a medical condition or someone who is recovering from physical trauma may rely on the sensor to monitor their heart rate. Thus, accurate reading of a user's physiological condition (e.g., heart rate) and encouraging the user to utilize (e.g., grasp) the sensor(s) may be very important.
Detecting a physiological condition typically involves the placement of sensors on exercise equipment in locations at which a user is likely to make contact with the equipment. When grasped, the sensors detect a physiological signal (e.g. a pulse), which is then processed and analyzed. In some cases, the exercise machine automatically changes its operation (e.g., changes a speed or load) in response to the reading. In other cases, results (e.g., a heart rate) are merely displayed. However, in all cases, the sensors cannot acquire accurate information without sufficient contact with a user's skin. In other words, each sensor must make sufficient contact with the user's skin to accurately measure, detect, or monitor the physiological condition of the user. When a user's skin does not make sufficient contact with the sensors, the sensors may collect erroneous physiological information or no information at all.
While the most commonly used sensors employ metal electrodes, such electrodes have drawbacks. For example, perspiration from a user that is exercising is transferred to the electrode, making its surface difficult to grasp. Sustaining a grip in the proper location and with sufficient contact pressure on the electrode can be a considerable challenge, particularly as the user fatigues or loses focus on their grip. In particular, when a user's grip on the electrode and, thus, the contact pressure applied to the electrode is inefficient it could result in inaccurate physiological condition information (e.g., an erratic displayed heart rate), perhaps deterring a user from using the exercise machine or reducing the effectiveness of the exercise.